This long overdue demo shows how I defeated the level 24 boss, on ACE difficulty. Yep, finally got around to recording it. :-)

Unlike my other boss demos, this one starts outside the yellow door. I do this because there is a switch behind it that is important to the red room tactics.

The yellow area is a single medium-sized room that houses the red key and quite a welcoming committee. :-) For expediency, I "waste" an earthshaker to eliminate most of the resistance. It's easy enough to dispatch the remaining little green gnats in conventional fashion.

Once inside, I re-stock my homing missiles (although I'm not sure why -- they're pretty useless against the boss :-) and shields, then I trigger two switches. The first removes the grate protecting the red key. The second apparently does nothing, but it does give the message: "door unlocked." Turns out that the door that it unlocks is inside the red area, and it provides access to the two 'Shakers that you can see behind the fence at the "bottom" of the "station."

OK, now it's on to the red room and the final encounter! On the way, I meet a couple straggling "Minefish," but they just slow me down a little. The route to the red room is important, and it requires planning early in the level. From the start, if you go right and follow the tunnel around to the left, you will encounter a green "Homer Hulk." This 'bot "always" drops an invulnerability sphere when he dies (at least in my experience). I save this until the end, when I am on my way to my date with the boss (like I am now :-). Be careful not to go "up" this vertical ring, though, as a fence will appear between this invulnerability and your shortest route to the red door.

So, now I enter the red room invulnerable. (Side note: there is an interesting demo playback bug evident in this demo -- at least on my system. The red door appears to be already open when I arrive.) I do not enage the boss just yet. The first order of business is exposing the secret room that contains two invulnerabilities and two 'Shakers. You can see this room from the outer, horizontal ring.

To gain access to this area, you must trigger three switches. The first is in a secret compartment, dead center in the "ceiling." Also in this compartment is another invulnerability (yes! :-). This removes a wall, off to the right of the red door through which I entered.

The second switch is behind this now removed wall, nicely hidden behind a fence in the ceiling. This exposes an area deeper in the wall. Finally, the third switch is in a secret compartment in the ceiling of this newly-exposed area.

I'm still invulnerable as I collect the 'Shakers, but it's almost gone, so I wait for it to expire, and pick up one of the two new ones in this room. Now, it's time to formally make acquaintance with the boss.

You may or may not know that the boss is vulnerable in only one spot -- his butt! There is a flashing green target located there! :-) It's hard to get a clean shot at this area, even when cloaked (surprisingly), so the best tactic is to shoot 'Shakers into the wall behind him. The blue blobs of destruction will home in on his weak spot, providing he doesn't teleport away.

So, what follows is a series of firing 'Shakers at the wall and returning to grab an invulnerability when my current one is about to expire. During this sequence, I also get the 'Shakers from the cage at the bottom of the station. Turns out I didn't need them, as I finish with two spare, but I sure felt better having them on-board. :-)